In the continued development of air-conditioning furnaces, one important consideration is to reduce acoustic emissions. For example, for forced air gas and oil fired residential air-conditioning furnaces, the furnace itself may be located in the building which is being heated in a location within the building where acoustic emissions are annoying to occupants of the building, or such emissions otherwise interfere with activities in the building. Accordingly, efforts have been made to reduce acoustic emissions caused by the combustion process as well as noise generated by airflow to and through the furnace.
However, prior art efforts to provide properly designed burner and burner box assemblies adapted to reduce acoustic emissions have not provided for as much reduction in such emissions from the burner box as desired without impeding airflow to and around the burners. Provisions for adequate airflow for proper combustion are, of course, important. Also of importance is to provide for the direction of the airflow to be such as to minimize any unwanted convection of heat in a direction which would reduce the thermal efficiency of the furnace. Accordingly, continued improvements in furnace burner box assemblies which provide for reduced acoustic emissions without restricting or misdirecting airflow have been sought. It is to these ends that the present invention has been developed.
The present invention provides a furnace burner box assembly having reduced acoustic emissions.
In accordance with one aspect of the present invention, a furnace burner box assembly is provided which includes one or more gas or oil-fired burners disposed therein and wherein a top wall of the burner box includes a large inlet opening for combustion air, and a multiple louvered baffle member supported on the underside of the burner box top wall. The burner box assembly also advantageously includes a second baffle member supported on the topside of the burner box top wall for reducing acoustic emissions from the burner box caused by the combustion process and by relatively high-velocity airflow into the burner box and then into the furnace heat exchanger in the combustion region.
The present invention also provides a burner box assembly with reduced acoustic emissions wherein a first baffle member is arranged depending from a top wall of the burner box and is provided with multiple air outlet openings for directing combustion air in a more even distribution through the burner box assembly. Multiple openings in the first baffle member are provided by louvers which form an angle with respect to the baffle bottom wall. The louvers are advantageously oriented to prevent direct or so-called line of sight noise transmission from the burner nozzle outlets to and through the primary combustion air inlet opening in the top wall of the burner box. Accordingly, the combustion air flowing into the burner box assembly is more evenly distributed, flow velocities are reduced and acoustic emissions are substantially prevented from exiting the burner box through the opening in the top wall. Still further, a second baffle member is mounted above the burner box top wall and further reduces acoustic emissions from the burner box assembly without impeding airflow thereto.
Those skilled in the art will further appreciate the above-mentioned advantages and superior features of the invention together with other important aspects thereof upon reading the detailed description which follows in conjunction with the drawings.